MA1009-CS120119 Responsive Service. Reliable Results.
AT' TEAGUE NALL AND PERKINS
Civil Engineering Surveying Landscape Architecture Planning
January 19, 2012
Mr. Keith Marvin, P.E.
Project Engineer
City of Coppell
255 E. Parkway Blvd.
Coppell, Texas 75019
Re: Alex Drive Canal Improvements
Dear Keith:
Enclosed you will find our submittal of alternatives for the reconstruction of the eastern wall of
the Alex Drive canal. These are the same drawings and estimates I submitted to you via email.
In addition to the evaluation of wall construction alternatives, TNP was to also prepare a
hydraulic model to verify no adverse impact of the wall improvements on peak water surface
elevations. Our hydrology/hydraulics team performed three separate models that reflect all six
wall options, and confirmed that none of them will create an adverse hydraulic impact.
TNP utilized the services of Rudi Reinecke at Integrated Environmental Solutions to evaluate
the project site with regard to Section 404 permitting. His study did confirm that the canal can
be identified as waters of the United States and would be regulated under Section 404 of the
Clean Waters Act. Furthermore, the type of work being proposed would be authorized under
Nationwide Permit 3 — Maintenance, and would not require a pre-construction notification to the
US Army Corps of Engineers. With regard to the various wall improvement alternatives,
Options 1, 2, 5, and 6 comply well with NWP 3. Options 3 and 4, due to the significant
horizontal relocation of the wall, would not fall under NWP 3 because they are changing the size
and capacity of the pond.
I think it would be helpful to discuss these alternatives and their respective pros/cons in a
meeting soon. Please let me know what works for your schedule once you have reviewed the
information. We appreciate the opportunity to be of service to the City of Coppell, and look
forward to continuing work on this project. If you have any questions, please let us know.
Sincerely,
TEAGUE NALL AND PERKINS, INC.
Mark J. Hollida Y, P.E.
Principal
12160 North Abrams Road, Suite 508 Dallas, Texas 75243 214.461.9867 phone 214.461.9864 fax
www.tnp-online.corn
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